>> on lectures and history, colorado professor sutter talks about how the rise of commercial fertilizer affected trade in farming practices. 1800s, farmers looked for nitrates to enrich their soil, and traditional methods, such as field rotation. this is about 50 minutes. prof. sutter: my name is paul sutter, i am a professor here at the university of colorado, boulder. this is an introduction to global history. today, our lecture is on agriculture and the fertilizer revolution. we began this course talking about agriculture with regards to the unending frontier, the expanding across the world, and the birth of the plantation complex in tropical regions. andher critical storyline

the environmental history of agriculture has been agricultural intensification. the growing, intensifying land-use to get more crops out of those lands. this coincides with the industrial revolution, which inated a real need for those europe and the united states to really concentrate on increasing food production to escape the that population would grow faster than a food production. there was the green revolution, where modern agriculture and genetic engineering was introduced to the developing world. today i want to talk about the 19th century and the fertilizer revolution. in a most general sense, a shift away from close to systems of fertility wasoil

raised within the farms and various ways. and we will talk about that. a and openged to system where concentrated forms of soil fertility were imported into the farm. and brought out intensively, used nutrients off the farm, out of soils, and away from the land. this became an open system of nutrient cycling. term, i gote this this also from karl marx. i mean a breakft in the chain of nutrient cycling first on the farm and then between the city and the countryside. with traditional sources of fertilizer becoming waste and new sources of fertilizer needed. what we will see then is the

industrialization of soil fertility. the transnational story, i will tell it that way, with a focus on the united states. before talking about that, let's step back for a minute and look at what soil and soil fertility is. soil is one of the most important natural resources. result of several processes. the first is simply the breakdown of what is called parent material like rock and matter thato loose provides minerals for plants to grow. the second is the breakdown of organic material which combines with this broken down parent material and gives soil its physical, neural structure. finally, recognize soil as a living thing.

sorts of insects, worms, microorganisms at work in soil that are critical to plants and crops' growth. soil characteristics are biological, physical, and chemical. plants need all sorts of things to grow, it is pretty basic. they need sun, water, carbon dioxide. also need nutrients, macronutrients in particular, like nitrogen, phosphorus, and potassium, the holy trinity of effective fertilization. micronutrients, we won't talk about those as much today. most macronutrients come from the breakdown of soil, but the most troubling one would be nitrogen. that is at the heart of today's story. let's talk about the nitrogen cycle, i know this is a history it goesut it turns out

-- undergoes a dramatic historical change during this period. it is a cycle of nitrogen between land and atmosphere. this is worked out largely in the 19th century. before that, people did not fully understand the nitrogen cycle. we now know the atmosphere itself is about 79% nitrogen. that atmospheric nitrogen is a critical source of nitrogen for plants and plant growth. is not immediately available to plants. and this is the most critical point we have to make, it is n2 at him.n this they cannot breathe nitrogen, so it has to be made bioavailable to them. i think we talked a little bit about this before. one is a lightning, which can fix nitrogen in the soil, that is an unimportant part of the cycle, but worth knowing.

ways are by soil microorganisms. some of which are symbiotic with a type of plant called a legume. they have the capacity to pull nitrogen out of the atmosphere and put it in the soil in ways that make it available to plants. to the planting of leguminous plants like peas, soybeans, peanuts, black-eyed peas, lentils, these were all crops that have the capacity to fix nitrogen from the atmosphere into the soil. non-symbiotic bacteria that can do this, as well. but legumes are critical. earth has a natural nitrogen cycle, nitrogen is constantly cycling in the atmosphere and in

the soil. it is a result of decomposers, and d nitroria, trifying bacteria. bunnies apparently help in this process. [laughter] to emphasize, one of the products of the metabolic rift i referred to, is the human transformation of the nitrogen cycle into the 20th century. that may not make a lot of sense to you right now, but i promise i will get to it and explain it in some detail. but we're getting ahead of ourselves. criticalk about the problem here, how do farmers over time maintain soil fertility on the lands they are farming? thisefore we get to

fertilizer revolution, i want to suggest a of ways in which they did that. perhaps the most important, early on, was shifting cultivation. , theifting cultivation dominant mode of fertilizer management worldwide. it was an approach whereby farmers would clear it a piece of land, usually for us, usually using fire to burn off and make nutrients from organic material immediately available. fire and out that the the ash produced has a basic ph which could correct for acidic soil. thatrs would then farm cleared land for a certain period of time, taking advantage of the natural fertility in the soil. producing, -- when the fertility began to wane, farmers would move on and clear a new piece of forest and

let the oldfield revert back. they might come back around to it, but decades later when it had regrown backup and restored its capacity to be fertile as a result of that regrowth. practice on a small scale, was , and noty sustainable that damaging, ecologically. aough it was and still is land-intensive way of farming. it required a lot of land. forher way to think of it, the little piece being farmed at any moment, there has to be a lot of land available so the farmer can then migrate. does that make sense? that was one of the most important ways in which farmers managed soil fertility in the past. and typically in tropical regions. we will talk about why that is the case in later lectures.

,urns out tropical soils burning is a good match for them. having focused on slash and burn as a strategy, a tremendous number of american farmers also practice this, particularly in the american south. that was where plantation crops were grown like tobacco and cotton. would farm the land until its productivity was worn out, and then they would move on. ais actually created caricature of the southern farmer as a soil-mined. someone who did not care for the land, when out and clear the land, took the nutrients out --

of course, they were growing staple crops like tobacco and cotton -- they would mind the nutrients and then move on. a lot of agricultural farmers and others who valued the stable, sedentary agriculture saw this as a particularly -- they or wasteful would not say destructive, but that is what they meant. there was an attachment in places like the american south to being more settled and civilized. and his brand of agriculture seemed messy. it actually seemed a lot like american -- native american agriculture. and burnticed slash cultivation for the most part. fallow.rest a farmer might own hundreds of thousands of -- thousands of

acres of land, but only farmed a little at a time. that farm base was there so they could cycle there terrible -- their arable land throughout a 20 year cycle. it did not look good, but it was potentially sustainable. use andourse, this land soil fertility management system, combined with slavery in , southern farmers were particularly interested in maximizing their investment in slaves. to do that, they had to get as much productivity out of the land as possible. in the context where there was a lot of land to be had, and there was not a lot of labor to be had. there was an economic logic rooted in slavery to the alliance upon shifting cultivation of the strategy first soil fertility management. clear so far?

questions from anyone? thell charge more to interesting stuff. another way of managing soil fertility, i will mention this quickly and move to another system. manure. what do usually think of, when youth here the word mentor -- manure? animal manure. here, youfallowing would farm a field for a while and let it rest. probably not enough for agriculture to be sustainable. a lot of farmers required on ground maneuver -- manure. but also night soil, and human waste. materials near the

ocean, seaweed, leaves from the park. also, the use of cover crops and legumes, sometimes plowed into the land. to these were important return nitrogen and other macronutrients to the soil. things aboute two them farmers did not always love. one, they were labor-intensive. shipping was labor-intensive, applying manure was, too. it did not allow for the maximization of one land for commercial production. that is an important point. for agriculture to be a more land-indeterminate thing. with this model of soil fertility management, we see in great britain across the 17th

and 18th centuries, and emerging revolution that allowed for much more intensive agriculture on set pieces of land, sustainable over the long-term. i will explain this quickly, it is complicated. it involves replacing fallow land, land outd of production, replacing it with improved pasture. pasture grasses, some of which were luminous. they were used for human and animal consumption, and grain and other marketable crops. and then pasture. the idea is that you're devoting a substantial part of your form to growing things the animals are going to eat.

that animal digestive process will produce a really high-quality maneuver, especially if you're using turnips. farmers became very careful g,ewards of this manure, dun as they called it. effectively, to within the bounds of a permanent, settled farm, raised efficient soil fertility as to keep thosere farms producing indefinitely. they would move pastors to farmland to clover, and rotated through the farm, so the nitrogen-fixing of the clover would be used for grain farming later on. this was a very effective system, called convertible husbandry. managed to retain soil fertility really effectively. but it was incredibly

labor-intensive. it meant that only a small portion of one plant at any given time could produce crops for market. for those reasons -- there is in they a reform american south of that tried to get southern farmers and planters to raise more livestock and improve their pastors, and to produce high-quality manure in a way that would allow them to settle in place, and not be shifting. engaging in it did not work, because they were more interested in using fresh land to produce big crops of tobacco and cotton and maximize their capacity to market these crops. this was a really important, and pretty powerful way, of raising soil fertility

in a closed system. this became the best model of the western world for a closed system for fertility maintenance. now we will look at how the system gets cracked open. that, i want to take a quick digression, and that is what happens to fertility management as people urbanized more and more. as more and more people are concentrated in urban areas, urban areas themselves become places that have a lot of organic nutrients that need recycling. that happens in a variety of ways. from greatight be britain, a figure known as the they would goan, around to household and collect any rags that people might have, or bones, as a result of cooking

or slaughtering livestock. do you know what the rags were used for? rags were the critical resource for papermaking in the 19th century. ragrmaking relied upon recycling, but the bones were used for fertilizer. these folks would aggregate huge bones.ions of rags and this is a photograph from baltimore, a figure called the nightsoil man. he would go around and collect human waste. there was indoor plumbing, so all of these wastes were collected in privies. surprisingly, not

that this is an african-american worker. this worker would collect the wastes and take them to the countryside. i will show you that in a minute. do you know what that is? this is a street scene in lower manhattan. , one of thee manure greatest sources of fertility. and all of these things, nightsoil, bones, horse manure, would be brought out into the , and bee hinterlands dumped on the farmlands. places like long island, those wereueens, agricultural hinterlands in new york's early history. they would produce a lot of crops for urban consumption.

and they would get the urban waste recycled back to their land. not a metabolic rift. but let's move in that direction. one last thing. anyone know what this is a picture of? >> american bison. prof. sutter: yes. these are bison bones. hunted bisons on the american planes almost to extinction. when the bison were all but gone, commercially extinct, the next industry that hit the great plains was an industry to collect bones, which were then ground up into fertilizer. the question? extinct? bison species prof. sutter: no, it is not. but it was the subject of intense market hunting. there were sealed -- so few left, there was a growing

conservation movement to keep them from going extinct. and now they made a big comeback, although a lot of the bison we see, are crossed with beefalos. they are there is a genetic mix there. a sense of how important bones were to the fertilizer trade. a quick scientific foray. soil science is also critical to the story. i won't bore you with too many details. coming into the 19th century, scientists believed in the humus theory of soil fertility, the idea that it was fertile because of the organic matter and manure s that breakdown into it. this is a model of soil fertility that i think anyone is spent time doing organic farming would be familiar with.

it made a bit of a return. chemist,man, a german insteade this and opted for a reductive soil chemistry that began to argue that fertile soils relied upon a couple critical nutrients. potassium, phosphorus. there will be a three number ratio, the ratio of those three elements. he is one of the ones that encourages us to think of fertilizer as more like vitamins then food. theory saw soil as something that needed to be fed. but no, it needed in fusions of these chemical, mineral elements.

nitrogen would be the trickiest one. but as luck would have it, just writing his major treatise on the subject in 1840, and industry was beginning to newtalize on a remarkable sort of concentrated, mineable, nitrogen, that came from an unlikely, remote place. the chinchas called islands. anyone know where these islands are? >> i would like to ask where these islands are located? [laughter] prof. sutter: anyone know? >> they're located off the coast of peru. you asutter: i will show map later. it is a very small island, three of them granite, off the coast

of southwest peru. as hosts for massive colonies of sea birds, pelicans, who would come to these islands, and had been for hundreds of not thousands of years, urinating and defecating on these islands in huge numbers. a sense ofive you the magnitude of this because it is actually quite staggering. in some places, and we will see some pictures, people who came these deposits found them to be about 150 feet deep in some places. how could this be? a couple things important about the ecology of these islands, there was the humboldt current

that brought nutrients out of the deep sea water and up to the surface, which fed small fish, in this case, anchovies. huge schools of anchovies around there which allowed the sea birds to feed without abandon on them. process this fish fertilizer throughout their digestive tract. the islands also exist in a rain shadow from the andean mountains. they get about one inch of rain fall a year. why is that important? >> no rain shadow means there was no chance to wash it away to get harvested. prof. sutter: in this case, the lack of rainfall effectively is no washing away or leaching of this. guanot other places, bird

would've been washed away or leached away. -- pure, almost to her geological deposits of bird crap . peruvian used by native people for hundreds of not thousands of years. question then humboldt , when he made note of these deposits and took peruvian quando back to him with europe where he had chemists tested and found it was incredibly rich in nitrogen. the first deposit to the united order of the editor of "the american farmer," in 1824, and within decades, as others confirmed guano's

fertilizing power, and international trade was developed in peruvian guano. thing.y important sorry i am a little behind there, there is my slide. as always, i will post these, so if you do not get a chance to jot these down now, they will be here. here are early illustrations of these islands. these are, effectively, guano deposits. you don't believe the etching, there is another one. i will show you some photographs in a minute. alexander von humboldt, brought it back. they are light and easy to transport. so unlike manure or nightsoil,

it comes in a -- a light, easy to transport package. another part of the story that toimportant to understand, mine these guano deposits would be incredibly awful work. have any of you ever cleaned out a chicken coop? magnify that about 100 annual get an idea. acriduano was incredibly and dusty and get into people's lungs and make them sick. anyone wanted to do. not surprisingly, the earliest juan o farmers were slaves -- guano farmers were slaves. peru outlawed slavery in the 1850's, and it was increasingly fed by a trade in chinese labor. some of it coming from the

coast. about 100,000 laborers from labor wasi-free brought to peru. many of them ended in the chincha islands where they had to work off the cost of their transport, mining guano. it was awful work, they got paid very little. fertilityeated the revolution in the developed world. it is also a story about the decline of slavery and the rise of other types of global labor and migration. also a really major problem, particularly among the chinese workers, who often kill themselves because the work was so awful.

here's a look at one of the sheds, and the deposits. here with guano carts there filling. they would then put them in , to take to chutes the united states and europe. 1840 -- there is an ad for pacific guano. of just a look at the period kuan no export, really peaking and 1870's. a little decline there, and then going down again after that. this period, exports were more than 12.6 million metric tons.

talk about mining. relationshiphis in to our lecture on coal mining. there is a real analog here between tapping into these fossil forms of soil fertility and the shift in organic to fossil fuel regime. retained control of the islands, but it was dominated by british trade myers out of liverpool, and another at of london that had a motto applied the house of gibbs made its dibs selling the turns -- turds of foreign birds. it was almost certainly the case that the potato blight that crop undo the irish potato

in 1840's and prompting massive wave of irish immigration, would walk from south america to europe. there is another little interesting tidbit of the columbian exchange. was sold tos guano french sugarbeet farmers. but probably half of it went to british agriculture to help grow food for the industrialization of britain. about a quarter of it went to the united states. not surprisingly, a lot of it went to the american south, to helped restore the fertility that some planters had worn out. increasingly, the importance of guano to american farmers led to political calls to break the peruvian monopoly. fillmore, one of the less memorable presidents and our history, dedicated a

substantial part of his annual address, the state of the union, in 1850, to the need for the united states to find strategic guano reserves. it was to mid-19th century politics with oil is today. 1856, and i should get my slide here, congress passed the guano islands act of 1856. what this act effectively did, it allowed american citizens who might be searching for new guano islands in the pacific or caribbean, if they found a new islands covered in guano, and/or otherwise unclaimed, to claim these islands a sovereign territory of the united states. islands act of 1856.

and this huge guano island rush. other guano islands had much smaller deposits and were much less rich in nitrogen because of rain leaching. nonetheless, there was a rush to find it. this is a bit of a digression, it did not articulate comfortably with the u.s. system of incorporating into nations. westward moving americans usually would settle a territory, and it would be incorporated into the nation as a territory and then estate. islands wouldo never become part of the united states like states.

they would just be islands connected in formally. let me read the language of the act. whenever a citizen of the u.s. not within the lawful jurisdiction of any government or occupied by the citizens of any other government, and takes peaceable possession thereof and occupies, such an island may, at the discretion of the president, be considered as appertaining to the united states. that phrase, appertaining, would be absolute critical at the turn of the 20th century when the united states becomes a colonial nation. colonies likesome the philippines, guam, puerto rico, etc. it does not create mechanisms allowing them to become part of the united states. there are a series of supreme court cases, insular cases, that

create the legal justification for the taking of colonies. and what others rooted in? islands act of 1856. at any rate,, guano is hugely important for these industrial centers in the united states and europe. eventually it plays out. the search for concentrated nitrate fertilizer shifts to another really interesting place. thehis case, a place called desertesert -- atacama in chile. anyone been there? >> it is one of the world's and one of the, driest places as well.

is one of the driest places on earth, that is important. it has incredibly rich sodium nitrate deposits, nearly a -- pure. a rock-like layer found under a gravel surface. very quickly, this becomes the next site for mining nitrate fertilizer. here by peruvians, andvians, and chileans, debt-peonage labor. it was mostly underwritten by british and american capital. a man became known as the nitrate king and dominates the

system, owning 70% of the industry. nitrateslean effectively replaced peruvian , and they also rely on sacks, most of jute of which are grown and processed in ben goll -- bengal. this slide is a little blurry, but the atacama desert is here. and like the chincha islands, it is the andean rain shadow that makes for the rich ecology. most of these nitrates went to britain and germany. in the united states, they particularly said the growth of the citrus industry in california. theean nitrates going up

pacific coast and feeding california agriculture. the nitrates trade would last into the 1930's. i think i have a similar slide here. great article by idea ofr, gives you an the spiking in the early 1930's. i will explain that cut off in a minute. >> were companies and governments actively looking for these huge deposits of nitrates, or just stumbled upon them? prof. sutter: a combination. i quickly went through that story about urban fertilizers. one of the important things about that, of course -- horse bones, thattsoil, created a fledgling commercial

fertilizer industry and got people in the habit of thinking about fertilizer as being something they don't necessarily raise on the farm but can purchase in commercial marketplaces. those supplies, like bones from bison, proved increasingly inadequate. people looked elsewhere to find those things. i focused particularly on areates, but phosphates analogous, but slightly less interesting. it was stumbled upon. trade att was urban cause people to think about fertilizer as a commercial commodity. and is it was liebig reductive chemistry. eventually people said, we know we need nitrogen, where can we find it? theory, thisus approach might not have made quite as much sense. does that answer the question?

good question. south, they did not use a tremendous number of chilean nitrates. we will see some ads, european. they ended up shifting to a different source of fertilizer. this is a fish called the menhaden. it is like an anchovy, a very small fish. it is a plankton feeder. it exists in huge schools in the atlantic ocean. does anyone know what it is harvested for today, it is controversial? there is a company called omega that harvested these for fish oil, or supplements for human ingestion.

menhaden came to replace wales as whales were increasingly extinct or hard to find as a major source of oil. . once at oil was pressed out of them, and they are fish that are not good for eating, their bony and oily. once they were pressed, they became an important source for commercial nitrates. now we are mining the seas defined nitrogen fertilizer to feed, mostly tobacco and cotton farming. still one in which very poor bringrners are trying to crops of cotton from increasingly degraded land. usually they are in land, one of the reasons, because they are buying a lot of fertilizer.

also, phosphate fertilizer being ned from south carolina, and later, tennessee. any questions? >> how long did they use the menhaden fertilizer? prof. sutter: they still do, to a certain degree. the end of my story would shift fertilizer to animal feed. it was increasingly necessary for fertilizer, because of these. guys are fritz haber and carl bosch. his superiors in germany

that he had perfected a reaction capable of generated ammonia, from -- he had figured out how to mine the air of nitrogen. carl bosch standardize it into an industrial process. osch.ow it as the haber-b mining this from the air began in 1913. what else are nitrates used for? >> explosives, like for a war. ? prof. sutter: munitions. we were just about to enter into world war i. this process would prove really

critical to the german capacity to fight world war i. after world war i, there were all these industrially produced nitrates hanging around as farmers would then begin to turn to them. aroundhis long search the globe for nitrates, we have a fully industrialized process for producing nitrogen. the haber-bosch process after incredibly and energy-intensive process, we would not need guano or menhaden anymore. at least four people who could afford it. this brings to a conclusion these various metabolic rifts

occurring throughout this period . i talked about the urban fertilizer market. what happens to the rest of the world with the use of nightsoil and horse manure? organic,e to be so increasingly we have indoor wasteng, that takes our away, where these critical nutrients become what we call pollution. also cease to have so many horses in cities, and cease to have the manure problems as well. to travel theg world over to find these concentrated forms of nitrogen pollution. let me end by pointing out, sorry again, a slide behind, how haber-bosch process

transforms the nitrogen cycle. today, industrial nitrogen fix asian through the haber-bosch process, produces about 32 million metric tons. of the intentional contribution of legumes -- we also get nitrogen oxide from boston, another 25 million metric tons. combined, and you can do the math here, we are looking at about over 157 million metric tons but a human produced. the natural nitrogen cycle 110lf only cycles about million metric tons between land and air. so the human nitrogen cycle has become bigger than the natural one. >> what industrialization would diet,ffect, the changing

-- withng night soil the change of the diet of people during industrialization, with that change the viability of nightsoil? prof. sutter: all of this fertilizer would be critical to raising the foods that support one of the other critical things, the huge bison population growth. century, this kind of fertilizer was being used only in very particular paces. the vast majority relied upon shifting cultivation or our gannett nutrient cycling, some manure. increasingly they turned to this. , my you get is a result final slide. this is a map of the mississippi-missouri watershed,

which has become a huge source of nitrogen pollution. all of which runs downstream and a hypoxic dead zone. nothing can live in the gulf of mexico here because so much nitrogen fertilizer is being pushed into the gulf, creating huge plankton blooms, sucking all the oxygen out of the water. i will just leave you with a bat, in terms of what the end result of all of this is. last question, because we do have to end. >> what sort of long-term solutions do they have for this? can they remove nitrogen from it, whileand restore also reusing the nitrogen? my understanding,

that is very difficult. it would be a very energy-intensive process. it is important to get pharmacy is nitrogen and away less likely to leech large amounts out into aquatic ecosystems. all right, thanks all, see you next time. [captions copyright national cable satellite corp. 2016] [captioning performed by the national captioning institute, which is responsible for its caption content and accuracy. visit ncicap.org] asjoin us saturday evening we join students in college classrooms to hear lectures ranging in topics from the american revolution, to 9/11. xers and history are also available as podcasts. , or downloadsite them from itunes. >> next on american history tv, a panel of vietnam war veterans, including two prisoners of war

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